LT1 problems

z28 boy

07-31-2005, 07:45 PM

Hey guys my friend has a problem with his 95 TA. One day after he put gas he went crusing and about 2 hrs later the car started to sputter and shut off. Well after 2 days he brought to me and a friend cause we were doing his tranny. well we got the tranny in but the car runs like shit. It sounds like it has a cam, u can hear it chug the gas and u can definately notice that it missfireing really badly. We drove it yesterday with the diagnostic scanner plugged in and it was sending some crazy signals. It was saying the desired idle was 3148rpm, and that the top speed we hit was 3,783.4 it said the coolant temp was 11,xxx. Im starting to get really mad cause we cant test and see if the tranny came out right cause the car just wont run. Anyone ever experienced this before? Oh and its not the gas cause its been refueled since.

Viper_Storm

07-31-2005, 07:52 PM

Hey guys my friend has a problem with his 95 TA. One day after he put gas he went crusing and about 2 hrs later the car started to sputter and shut off. Well after 2 days he brought to me and a friend cause we were doing his tranny. well we got the tranny in but the car runs like shit. It sounds like it has a cam, u can hear it chug the gas and u can definately notice that it missfireing really badly. We drove it yesterday with the diagnostic scanner plugged in and it was sending some crazy signals. It was saying the desired idle was 3148rpm, and that the top speed we hit was 3,783.4 it said the coolant temp was 11,xxx. Im starting to get really mad cause we cant test and see if the tranny came out right cause the car just wont run. Anyone ever experienced this before? Oh and its not the gas cause its been refueled since.

bad ecm maybe?, lol, im just guesting.

Mr. Luos

07-31-2005, 07:57 PM

bad ecm maybe?
That would be my first test.

Viper_Storm

07-31-2005, 08:01 PM

That would be my first test.

yea, why else would it be shooting out numbers like that? it was just first thing that came to mind

FormulaLT1

07-31-2005, 08:01 PM

If all the PCM readings are off. Its either a burnt up ground or the PCM went bad. Also you were using a OBD 1 scanner right?. Cause the 95 has the obd 2 terminal but obd 1 pcm. If the pcm , you scans ok later on but still causing all the problem. It sounds like a bad opti. Good luck man.

Viper_Storm

07-31-2005, 08:03 PM

whats a pcm?

FormulaLT1

07-31-2005, 08:05 PM

94 + GM F-body's used a computer controled tranny. The 4l60-e which means the vehicle computer now is responsible for tranny function so instead of being a "engine control module", its now a "powertrain control module".

Viper_Storm

07-31-2005, 08:08 PM

thats just for automatics or manual to?

FormulaLT1

07-31-2005, 08:09 PM

Both, ever heard of cags?.

Both Manual and auto 94 + LT1 use the same computer, just the eprom is programmed differently.

Rally Sport

07-31-2005, 08:12 PM

Use some STP, injector cleaner, if you will too.

Viper_Storm

07-31-2005, 08:18 PM

Both, ever heard of cags?.

Both Manual and auto 94 + LT1 use the same computer, just the eprom is programmed differently.

nope, never heard of cags, first time acctually. so what do they control? btw im sorry for taking this thread a lil off topic.

FormulaLT1

07-31-2005, 08:23 PM

Cags (Computer Assisted Gear Selection) is a skip shift system programmed into 6 speed F-bodys and vettes PCM's. It doesn't allow you to use 2nd or 3rd gear under certain throttle conditions. It instead routes you to 4th, to allow for better fuel ecomony. Therefor controlling tranny function.

Viper_Storm

07-31-2005, 08:32 PM

Cags is a skip shift system programmed into 6 speed F-bodys and vettes PCM's. It doesn't allow you to use 2nd or 3rd gear under certain throttle conditions. It instead routes you to 4th, to allow for better fuel ecomony. Therefor controlling tranny function.

oh, i have heard of skip shift before, ook, thanks for explaining this :)

Rally Sport

07-31-2005, 09:05 PM

Would that interfere when you're trying to race or no?

FormulaLT1

07-31-2005, 09:08 PM

Under heavy throttle conditions it allows you to use 2nd and 3rd from what I hear but I have never raced using the t56 so that question would be answered better by Mr.Luos

Viper_Storm

07-31-2005, 09:10 PM

Would that interfere when you're trying to race or no?

lol, as always hes offline (again).. im willing to bet no, as in a race you are WOT its not like bumper to bumper traffic where you might get just enough speed&rpms to get you into 2nd then you sit there and linger at low rpms in second... again im only guessing here i dont know for fact.

z28 boy

07-31-2005, 09:19 PM

Would us trying another pcm from a 95 model LT1 work? Another thing yall brought up is a burnt up ground, that sounds like a possibility cause he had a stereo system hooked up to the battery with out a fuse. The power wire was kinda loose and its possible that, that could have caused the burnt ground right? U know if the power wire made sudden jerks away from the battery.

Rally Sport

07-31-2005, 09:38 PM

Yup..always off..

FormulaLT1

07-31-2005, 09:49 PM

Yes, swapping in another 94 - 95 PCM would pinpoint if thats the problem. Also I would check all the ground points to see if thats whats causing the problem. There are 2 ground lugs attached to the left of the coil and a ground strap there. There is also a body ground wire that goes from the battery to the passenger side fender well. There is a PCM ground above the start and towards the front and a engine battery ground strap also on the passenger side attached to a nut for the motor mount. I would check all those locations for possible damage or burnt wire. Good luck and check http://shbox.com/1/component_location_views.html for some close ups of these locations.

John

z28 boy

08-05-2005, 03:25 PM

Once again thanks guys, i know this thread is old by now but i just got back from vacation. I was told that the car was acting like that because of a vacumn leak, well the car is up and running any way.